Dodge Ram Truck 1500-2500-3500. Manual — part 57

C1454-REAR DIFFERENTIAL POSITION SENSOR CIRCUIT HIGH

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DIFFERENTIAL & DRIVELINE - ELECTRICAL DIAGNOSTICS

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C1454-REAR DIFFERENTIAL POSITION SENSOR CIRCUIT HIGH (CONTINUED)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
The ignition on. Axle Locker Switch in the RR or FR/RR position.

•

Set Condition:
The FDCM detects that the Rear Differential Position Sensor is shorted to voltage.

Possible Causes

(T527) REAR LOCKER SENSOR SENSE SHORTED TO BATTERY VOLTAGE

REAR DIFFERENTIAL POSITION SENSOR

(T527) REAR LOCKER SENSOR SENSE OPEN

(T527) REAR LOCKER SENSOR SENSE SHORTED TO (T521) LOCKER SENSOR SUPPLY

FDCM

Diagnostic Test

1.

ACTIVE DTC

CAUTION: Before removing the FDCM harness connector, clean the connector and locking cam area of dirt
and debris. Failure to do so can result in the connector being jammed or damage to the locking cams on
the harness connector or module. Do not force the assist arm when releasing or installing the harness con-
nector.
Ignition on, engine not running.

With the DRBIII

T

, read DTCs.

Is the DTC active at this time?

Yes

>> Go To 2

No

>> Go To 7

2.

(T527) REAR LOCKER SENSOR SENSE SHORTED TO BATTERY VOLTAGE

NOTE: Before continuing with the below diagnostic test, ensure
the FDCM harness connector seal is installed correctly. Inspect
the terminals on both harness connector and the module for
damage. Failure to do so can result in misdiagnoses of the sys-
tem.
Turn the ignition off.

Disconnect the Rear Locker Solenoid harness connector.

Disconnect the FDCM harness connector.

Turn the ignition on.

Measure the voltage on the (T527) Rear Locker Sensor Sense circuit
in the FDCM harness connector.

Does the voltmeter indicate voltage present?

Yes

>> Repair the short to voltage in the (T527) Rear Locker Sen-

sor Sense circuit.

Perform FDCM VERIFICATION TEST.

No

>> Go To 3

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C1454-REAR DIFFERENTIAL POSITION SENSOR CIRCUIT HIGH (CONTINUED)

3.

REAR DIFFERENTIAL POSITION SENSOR OPERATION

Turn the ignition off.

Connect the FDCM harness connector.

Ignition on, engine not running.

Using a jumper wire, jumper across from the (T527) Rear Locker Sensor Sense circuit and the (T521) Locker Sen-
sor Supply circuit in the Rear Locker Solenoid harness connector.

While monitoring the sensor state on the DRBIII

T

, tap the jumper wire on and off the (T527) Rear Locker Sensor

Sense circuit terminal. Hold the jumper wire on and off the terminal for a minimum of 3 seconds.

Does the state change on the DRBIII

T

while tapping the terminal?

Yes

>> Replace the Rear Locker Solenoid.

Perform FDCM VERIFICATION TEST.

No

>> Go To 4

4.

(T527) REAR LOCKER SENSOR SENSE CIRCUIT OPEN

Turn the ignition off.

Disconnect the FDCM harness connector.

Measure the resistance of the (T527) Rear Locker Sensor Sense cir-
cuit between the Rear Locker Solenoid harness connector and the
FDCM harness connector.

Is the resistance below 5.0 ohms?

Yes

>> Go To 5

No

>> Repair the open in the Rear Locker Sensor Sense circuit.

Perform FDCM VERIFICATION TEST.

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DIFFERENTIAL & DRIVELINE - ELECTRICAL DIAGNOSTICS

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C1454-REAR DIFFERENTIAL POSITION SENSOR CIRCUIT HIGH (CONTINUED)

5.

(T527) REAR LOCKER SENSOR SENSE CIRCUIT SHORTED TO (T521) LOCKER SENSOR SUPPLY

Measure the resistance between the (T527) Rear Locker Sensor
Sense circuit and the (T521) Locker Sensor Supply circuit in the
FDCM harness connector.

Is the resistance below 5.0 ohms?

Yes

>> Repair the short between the (T527) Rear Locker Sensor

Sense circuit and the Locker Supply Sensor circuit.

Perform FDCM VERIFICATION TEST.

No

>> Go To 6

6.

FDCM

NOTE: Before continuing, check the FDCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.

Were there any problems found?

Yes

>> Repair as necessary.

Perform FDCM VERIFICATION TEST

No

>> Replace and program the Final Drive Control Module in accordance with Service Information.

Perform FDCM VERIFICATION TEST.

7.

INTERMITTENT WIRING AND CONNECTORS

The conditions necessary to set this DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle test the wiring harness and connectors while checking for shorted and open circuits.

Using the DRBIII

T

, monitor the data related to this circuit while performing the wiggle test. Look for the data to

change or for the DTC to reset.

Were there any problems found?

Yes

>> Repair as necessary.

Perform FDCM VERIFICATION TEST.

No

>> Test Complete.

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